diff --git a/clang/test/Index/availability.mm b/clang/test/Index/availability.mm
new file mode 100644
--- /dev/null
+++ b/clang/test/Index/availability.mm
@@ -0,0 +1,70 @@
+__attribute__((availability(macosx, introduced = 8.0)))
+@interface C {
+  int i0;
+  int i1 __attribute__((availability(macosx, introduced = 9.0)));
+}
+@property int p0;
+@property int p1 __attribute__((availability(macosx, introduced=9.0)));
+- (void)m0;
+- (void)m1 __attribute__((availability(macosx, introduced = 9.0)));
+@end
+
+@implementation C
+- (void)m0 {
+}
+- (void)m1 {
+}
+@end
+
+__attribute__((availability(macosx, introduced = 10.0)))
+@interface C(Cat)
+@property int p2;
+@property int p3 __attribute__((availability(macosx, introduced=11.0)));
+- (void)m2;
+- (void)m3 __attribute__((availability(macosx, introduced = 11.0)));
+@end
+
+@implementation C(Cat)
+- (void)m2 {
+}
+- (void)m3 {
+}
+@end
+
+__attribute__((availability(macosx, introduced = 10.0)))
+@protocol P
+@property int p4;
+@property int p5 __attribute__((availability(macosx, introduced=11.0)));
+- (void)m4;
+- (void)m5 __attribute__((availability(macosx, introduced = 11.0)));
+@end
+
+// RUN: c-index-test -test-print-type --std=c++11 %s | FileCheck %s
+
+// CHECK: ObjCInterfaceDecl=C:2:12  (macos, introduced=8.0)
+// CHECK: ObjCIvarDecl=i0:3:7 (Definition)  (macos, introduced=8.0)
+// CHECK: ObjCIvarDecl=i1:4:7 (Definition)  (macos, introduced=9.0)
+// CHECK: ObjCPropertyDecl=p0:6:15  (macos, introduced=8.0)
+// CHECK: ObjCPropertyDecl=p1:7:15  (macos, introduced=9.0)
+// CHECK: ObjCInstanceMethodDecl=m0:8:9  (macos, introduced=8.0)
+// CHECK: ObjCInstanceMethodDecl=m1:9:9  (macos, introduced=9.0)
+
+// CHECK: ObjCImplementationDecl=C:12:17 (Definition)  (macos, introduced=8.0)
+// CHECK: ObjCInstanceMethodDecl=m0:13:9 (Definition)  (macos, introduced=8.0)
+// CHECK: ObjCInstanceMethodDecl=m1:15:9 (Definition)  (macos, introduced=9.0)
+
+// CHECK: ObjCCategoryDecl=Cat:20:12  (macos, introduced=10.0)
+// CHECK: ObjCPropertyDecl=p2:21:15  (macos, introduced=10.0)
+// CHECK: ObjCPropertyDecl=p3:22:15  (macos, introduced=11.0)
+// CHECK: ObjCInstanceMethodDecl=m2:23:9  (macos, introduced=10.0)
+// CHECK: ObjCInstanceMethodDecl=m3:24:9  (macos, introduced=11.0)
+
+// CHECK: ObjCCategoryImplDecl=Cat:27:17 (Definition)  (macos, introduced=10.0)
+// CHECK: ObjCInstanceMethodDecl=m2:28:9 (Definition)  (macos, introduced=10.0)
+// CHECK: ObjCInstanceMethodDecl=m3:30:9 (Definition)  (macos, introduced=11.0)
+
+// CHECK: ObjCProtocolDecl=P:35:11 (Definition)  (macos, introduced=10.0)
+// CHECK: ObjCPropertyDecl=p4:36:15  (macos, introduced=10.0)
+// CHECK: ObjCPropertyDecl=p5:37:15  (macos, introduced=11.0)
+// CHECK: ObjCInstanceMethodDecl=m4:38:9  (macos, introduced=10.0)
+// CHECK: ObjCInstanceMethodDecl=m5:39:9  (macos, introduced=11.0)
diff --git a/clang/tools/libclang/CIndex.cpp b/clang/tools/libclang/CIndex.cpp
--- a/clang/tools/libclang/CIndex.cpp
+++ b/clang/tools/libclang/CIndex.cpp
@@ -8258,8 +8258,34 @@
           deprecated_message, always_unavailable, unavailable_message,
           AvailabilityAttrs);
 
-  if (AvailabilityAttrs.empty())
+  // If no availability attributes are found, inherit the attribute from the
+  // containing decl or, if the current decl is an implementation, the class or
+  // category interface.
+  if (AvailabilityAttrs.empty()) {
+    const ObjCContainerDecl *CD = nullptr;
+    const DeclContext *DC = D->getDeclContext();
+
+    if (auto *IMD = dyn_cast<ObjCImplementationDecl>(D))
+      CD = IMD->getClassInterface();
+    else if (auto *IMD = dyn_cast<ObjCCategoryImplDecl>(D))
+      CD = IMD->getCategoryDecl();
+    else if (auto *ID = dyn_cast<ObjCInterfaceDecl>(DC))
+      CD = ID;
+    else if (auto *CatD = dyn_cast<ObjCCategoryDecl>(DC))
+      CD = CatD;
+    else if (auto *IMD = dyn_cast<ObjCImplementationDecl>(DC))
+      CD = IMD->getClassInterface();
+    else if (auto *IMD = dyn_cast<ObjCCategoryImplDecl>(DC))
+      CD = IMD->getCategoryDecl();
+    else if (auto *PD = dyn_cast<ObjCProtocolDecl>(DC))
+      CD = PD;
+
+    if (CD)
+      getCursorPlatformAvailabilityForDecl(
+          CD, always_deprecated, deprecated_message, always_unavailable,
+          unavailable_message, AvailabilityAttrs);
     return;
+  }
 
   llvm::sort(
       AvailabilityAttrs, [](AvailabilityAttr *LHS, AvailabilityAttr *RHS) {